1. Field of the Invention
The present invention relates to an optical waveguide device for use in optical communications, and more particularly to a shock-resistant optical waveguide device capable of keeping input and output optical fibers stably connected to an optical waveguide without causing an axial misalignment therebetween.
2. Description of the Prior Art
Known optical waveguide devices have a casing in the shape of a rectangular parallelepiped, a base member supporting an optical waveguide substrate with an optical waveguide formed therein, the base member being fixedly mounted in the casing through a support member of resin, and input and output optical fibers extending into the casing through a bushing on the casing.
The conventional optical waveguide devices are disadvantageous in that they are unable to sufficiently resist external forces such as shocks, tensile forces, or the like, i.e., the optical waveguide and the optical fibers tend to be disconnected or axially misaligned when subjected to external forces.
In many prior optical waveguide devices, the optical waveguide and the optical fibers are spliced by directly bonding and fixing a flat end face of the optical waveguide to flat end faces of the optical fibers. According to one splicing process, it has been necessary to position the optical waveguide and the optical fibers three-dimensionally along X-, Y-, and Z-axes, and then adjust the angles of the optical axes of the optical fibers with respect to the optical axis of the optical waveguide along the X-, Y-, and Z-axes so that the optical waveguide and the optical fibers are axially aligned for higher optical propagation efficiency. If the flat end faces of the optical waveguide and the optical fibers are not sufficiently bonded to each other, however, they can easily be axially misaligned under external forces.
The gap between the bushing and the optical fibers which extends through the bushing into the casing is filled with an adhesive that is simply applied from outside of the casing, thus hermetically sealing the casing. If the adhesive contains air bubbles or the bushing and the optical fibers are bonded through an insufficient adhesive area at the time the casing is shocked, then the casing may not be kept hermetically sealed well.